<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<div id="app">
    <input type="text" v-model="username">
    <p>Hello: {{username}}</p>
</div>

<script type="text/javascript" src="../js/vue.js"></script>
<script type="text/javascript">
    const vm = new Vue({
        el: '#app',
        data: {
            username: null,
        }
    })
</script>
</body>
</html>